The present invention relates to a composition and method for using the composition to neutralize or reduce malodors and bad tastes. More particularly, the present invention is directed to the use of undecylenic acid, its esters and/or salts, with fragrance and flavor components, and in products containing same to provide for odor neutralization of undesired aromas and tastes while maintaining the effect of the fragrance and flavor components. The composition of the present invention comprises undecylenic acid, its esters and/or salts with desirable fragrances and flavors at such concentrations that scavenging of the desirable volatilized fragrance and flavor components are minimized while maintaining an effective scavenging activity for undesired aromas and tastes. The present invention finds application in a wide variety of products such as, but not limited to, fabric and linen spray, candles, carpet deodorizer, hand sanitizer gels, room sprays and oral care products such as dentrifrices and mouth washes.
Fragrances and flavors are often used to provide sensory aesthetic benefits. Release of a particular fragrance and/or flavor from a composition can serve as a signal that the composition is not fouled or ineffective, or may be associated with particular attributes such as a strength, cleanliness and usefulness. Fragrances and flavors are added to numerous consumer products to provide sensory signals indicating the quality and worth of the product.
The practical use of a composition may be limited due to fouling of the composition with undesirable contaminants, break-down products, or other materials which produce undesired aromas and tastes (xe2x80x9cmalsensory agentsxe2x80x9d). While prevention of the formation of malsensory agents may be deemed preferable, and may be practicable in certain circumstances, such as when antibacterial or antifungal agents are used to reduce the number of microorganisms which excrete malsensory agents, often it is not possible to prevent fouling of a composition used in an environment exposed to malsensory agents.
Undesired aromas and tastes in a composition may be ameliorated by chemical modification of the malsensory agent (e.g., by reacting it with reactant so as to produce a new composition, such as an adduct or further breakdown product which lacks an undesired aroma and/or taste), reducing the release of the malsensory agent from the composition (as by absorption and/or adsorption of the malsensory agent onto another compound such as charcoal or zeolites), reducing the vapor pressure of the malsensory agent (making it less volatile), or by removal of the malsensory agent from the composition (as by solvent extraction). Undesired aromas and tastes may also be ameliorated by judicious use of fragrances and/or flavors in amounts sufficient to mask the malsensory agent.
Numerous compounds, which range from non-descript plant extracts to single and multiple chemical entities, have been touted to reduce the sensory perception of malodors. For example, U.S. Pat. No. 3,923,005 to Fry et al. discloses the use of chlorophyll to remove the smell from used cat litter, while U.S. Pat. No. 4,989,727 discloses a deodorant consisting of deodorizing ingredients extracted from plants said to be useful for a wide variety of smells including sulfur and nitrogen compound odors.
U.S. Pat. No. 4,909,986 to Kobayashi et al., discloses compounds useful as deodorants including water-soluble organic polymers having an average molecular weight of at least 100,000.
U.S. Pat. No. 4,959,207 to Ueda et al. discloses a mixture of an undecylenic acid anhydride with a copper compound.
U.S. Pat. No. 3,091,511 to Calhoun discloses a salicylic undecylenic acid ester of phenol and p-acetylaminophenol.
U.S. Pat. No. 5,718,887 to Wolf et al., discloses xcexa9-alkanedicarboxylic acids and moncarboxylie acid-esters of oligoglycerols as useful in reducing body odor, and U.S. Pat. No. 5,534,165 to Pilosof et al. discloses beta-cyclodextrin as a deodorant.
Among the many compounds said to have deodorizing activity are undecylenic acid and its derivatives. Undecylenic acid (C11H20O3) is a naturally occurring acid found in tears and sweat. It is commonly derived from cracking C18, often derived from castor oil, into C7 and C11 (where C11 is known as undecylenic acid or undecanoic acid).
Undecylenic acid and its derivatives display interesting biological profiles which have been used in such diverse products as pediculicides (See, e.g., U.S. Pat. No. 5,416,116) and wild game repellants (to protect against the damage of cropsxe2x80x94See, e.g., DE-A-1,792,467). Initially undecylenic acid was proposed as a deodorizing agent based on its bacteriostat (See, e.g., U.S. Pat. No. 3,762,875) and fungistat activities (See, e.g., U.S. Pat. Nos. 3,882,868, 3,899,616 and 4,462,981) where bacterial and fungal break-down products are frequently malsensory in nature. Later it was recognized that undecylenic acid, and a number of its derivatives are effective deodorizing agents in and of themselves.
Undecylenic acid has been used as deodorant in several products, including animal litter boxes (See, e.g., U.S. Pat. No. 4,517,919 which discloses the use of undecylenic acid in a flexible absorbent pad for use in animal litter boxes). It has also been used in conjunction with other deodorizing agents to enhance deodorization. For example, U.S. Pat. No. 5,182,103 discloses undecylenic acid, among many other compounds, to be useful in combination with an aluminometasilicate coated composite to provide an improved deodorant for refrigerators, garbage cans, automobiles, leather insole for shoes, paper diapers, menstrual products and general in-room use.
Ester derivatives of undecylenic acid, in particular, have been found to possess significant deodorizing activity. Polyoxyalkylene and simple alkyl esters of undecylenic acid have been found to be quite useful in the treatment of animal excreta. For example, U.S. Pat. No. 5,275,783 discloses the use of polyoxyalkylene esters of undecylenic acid as useful for the deodorization of liquid manures, while U.S. Pat. No. 5,338,511 discloses the use of alkyl and polyoxyalkylene ester derivatives of undecylenic acid at a concentration on the order of 0.01% to 5% by weight as useful in the deodorization of sewage sludges. See also, U.S. Pat. No. 5,720,947 disclosing the use of undecyleneic acid, its esters and its polyoxyalkylenated esters in conjunction with superphosphates in the deodorization of animal excreta. Such ester derivatives have also found use in the deodorization of paper mill effluents (See, U.S. Pat. No. 5,439,641), the removal of odors from malodorous animal foodstuffs (See, U.S. Pat. No. 5,747,090 and EP-0-434-524 which disclose deodorization with an alkyl or polyoxyalkylene ester of undecylenic acid, and its methyl, propyl, hexyl and decyl ester derivatives), and the deodorization of paper products, cardboards and non-woven material, such as found in filters, vacuum cleaner bags, nappies and air freshener diffusers (See, U.S. Pat. No. 5,976,460). Use of undecylenic acid ester derivatives in conjunction with polyetheresteramide polymers as deodorants is also disclosed in European Patent Application Publication No. 0 596 772.
It is believed that undecylenic acid, and its derivatives, deodorize by forming an extended conjugated system that reduce the vaporization of malsensory agents thereby reducing the density of such agents in the gaseous phase by amounts detectable by the human olfactory receptors. This can be confirmed as shown by a decrease of the density of the agents in the gaseous phase by sophisticated analytical techniques, including gas chromatography and mass spectroscopy. It was generally believed that intimate contact created for example, by physical mixing or spraying between the undecylenic acid, or its derivatives, and the malodor producing agent is necessary in order for a reduction in malodor to occur.
The deodorizing action of undecylenic acid and its ester derivatives appears to be independent of the inherent aroma of the particular undecylenic acid derivative. For example, methyl undecylenate, a known carnation base (See, U.S. Pat. Nos. 4,137,677 and 4,250,001), and ethyl undecylenate, characterized by some as an xe2x80x9cenduring perfume ingredientxe2x80x9d, that is an ingredient that will remain on a fabric or body (as the case may be) throughout any rinse and drying steps (See, e.g., U.S. Pat. Nos. 5,500,137, 5,500,138, 5,500,154, 5,531,910, 5,790,404, and 5,849,310), as well as an xe2x80x9calcohol masking xe2x80x9d agent (See, U.S. Pat. No. 5,843,881), both reduce perception of malodors to a far greater extent than can be associated with any masking of the malodors by any aroma of the respective undecylenate ester.
Application of undecylenic acid derivatives has conventionally been limited to removing odors from non-consumable substances, such as sludges, personal care products, paper products and animal feeds. While many undecylenic acid derivatives are non-toxic, such acids and their derivatives have not been used to reduce mal-tasting flavors in human-consumed foodstuffs and expectorants (such as mouthwashes and dentifrices).
While undecylenate derivatives and their salts are quite effective at reducing malodors, they all suffer from a major disadvantage in that they are thought to scavenge both malodors and desired odors, such as perfumes and flavoring agents, without selectivity.
Therefore, there is a need for a composition and method that makes use of the advantageous malodor neutralizing and retention properties of undecylenic acid, its esters, and salts thereof, without disadvantageously affecting the release of desired aromas and flavors or negatively effecting the end use hedonics of such.
The present invention provides fragrance and flavor compositions containing malsensory agent neutralizing compositions for inclusion in a variety of consumer products. In particular, by pre-mixing the neutralizing composition with the fragrance at a defined ratio, the present invention provides fragrance and flavor compositions that permit enhanced neutralization of malsensory agents while permitting advantageous controlled release of the desired fragrance and/or flavor. The present invention further provides for prolonged release of fragrances, and without any undesirable aromas that may be associated with the undecylenic acid and/or its derivatives.
The composition and method of the present invention reduces undesirable scavenging of fragrances and flavors in products incorporating undecylenic acid, and its derivatives, by pre-mixing the undecylenic acid and/or its derivatives with fragrances and flavor agents in a medium such that the concentration of the undecylenic acid and/or its derivatives is from about 5% to about 50% by weight of the medium for the pre-mix, and then adding the resultant pre-mix medium to products or carriers which are desired to be deodorized or used for deodorization. Pre-mixture of the undecylenic acid and its derivatives with the desired fragrances and flavors at such concentrations has also been found to provide a composition with improved release of the fragrance and/or flavoring agent over time. What is meant herein by a composition with improved release of fragrance and/or flavoring components is a composition using undecylenic acid, and/or its derivatives with fragrance and/or flavor components wherein the release of many of the flavor and/or fragrance components is controlled over a time period that is longer than without the composition. This is most advantageous where greater fragrance longevity is desirable, while minimizing substantial diminution of fragrance or flavor impact or strength.
The present invention also produces the unexpected results where undecylenic acid, and its derivatives, in particular its ester derivatives, are useful for removing odors even in a non-aqueous environment. In particular, the unexpected results are that undecylenic acid, its esters and salts, and other derivatives, remain effective in removing odors even when allowed to volatilize into the air without mechanical assistance (i.e. spraying), or intimate contact. When formulated into a spray product, and directed onto fabric materials, undecylenic acid, and its derivatives, have unexpectedly been found to provide significantly better effectiveness in removing common place odors, such as tobacco smoke smell, feces odors, cooking smells, body odors and feminine odors than commonly used cyclodextrins (See, e.g., U.S. Pat. Nos. 5,534,165, 5,714,137, 5,668,097, 5,783,544, 5,942,217, 5,968,404). Particularly improved performance was seen with fragrance compositions for a pre-mix including about 5% to about 50% of undecylenic acid and/or it derivatives, more preferably wherein the pre-mix comprises 10-30% of a mixture of about 60-90% ethyl undecylenate with about 10-40% methyl undecylenate, the balance of the pre-mix containing fragrance and/or flavor component(s). The improved odor neutralizing performance of the pre-mix was also observed when used in a concentration of about 0.5-2.0% by weight in a fabric spray comprising, for example, about 0-40% alcohol, 0.2-10% surfactant, the balance being water. The specific combination of methyl and ethyl undecylenates allowed for the lower odor inherent in the ethyl undecylenate, and the greater efficacy of the methyl component at a low enough level so as to minimize its own solvent-like odor contribution, and obtain optimal malodor neutralization.
The use of compositions containing undecylenic acid and its derivatives in particular, the methyl and ethyl esters thereof, was unexpectedly determined to remove odors from the atmosphere in which such compositions were burned or heated, as in products that can maintain a flame, or products which utilize other dynamic energy sources. In addition, vaporization of the undecylenic acid, and its derivative, in particular the methyl and ethyl esters thereof, into the atmosphere was seen to remove malodors dispersed in such atmosphere even though the undecylenic acid/acid-derivatives were not in direct contact with the source producing the odor.
Particularly useful odor neutralizing agents were found to include undecylenic acid, salts of undecylenic acid (e.g., sodium, calcium and zinc), simple esters of undecylenic acid (e.g., methyl, ethyl, propyl, butyl), undecylenate silicone esters, and combinations of undecylenic acid esters.